Not applicable
Not applicable
The present invention relates to cleaners, particularly hard surface cleaners in which the cleaner imparts desired cleaning and surface appearance characteristics to the surface being cleaned while also disinfecting the surface being cleaned.
There are a variety of known hard surface cleaning materials, including a number which are designed for cleaning and otherwise improving the appearance of floors and the like. See e.g. U.S. Pat. Nos. 3,976,501, 4,443,363, 4,596,668, 4,880,558, 5,000,867, 5,348,678, 5,811,386, 5,965,514, 6,159,924 and 6,325,862.
There have also been suggestions to include in a hard surface cleaner a quaternary ammonium compound as a germicidal active to disinfect a hard surface while it is being cleaned. See e.g. U.S. Pat. No. 6,268,327. This patent specifically suggests the use of an alkyl dimethyl benzyl ammonium chloride compound, such as BTC(copyright) 2125M, as a preferred quaternary ammonium germicide.
There has also be some use of biguanide (a/k/a diguanide) antimicrobial compounds in cleaners (e.g. especially skin cleaners) where the cleaner kills bacteria on the surface it is applied to. See U.S. Pat. No. 6,071,866.
Also, it has been suggested to incorporate biguanides and/or ammonium compounds (such as benzylalkyldimethylammonium chloride) in cleaners to act as preservatives while the cleaner is stored. See e.g. European patent application 017,149.
It has been further proposed to included substituted guanidine anti-microbial agents in a sanitizing composition. See U.S. Pat. No. 5,000,867.
Some cationic polymers have also been proposed for incorporation in certain cleaning materials to improve cleaning effectiveness or impart desired attributes to the surface after being cleaned. See e.g. EP 017,149 and 6,251,849.
However, there is a continuing need to develop improved cleaning materials, particularly for floor care cleaners that require a disinfecting capability (e.g. for hospital maintenance). In this regard, formulation components that act as effective cleaners or disinfectants for floors may not be optimal for imparting desired residual characteristics to the surface (e.g. imparting shine; avoiding slippery conditions; avoiding unduly long periods for drying).
In some cases the art has split the cleaning/disinfecting and the surface treating functions into two separate products. It is much more desirable to have a single step (xe2x80x9cone-stepxe2x80x9d) product that addresses the needed cleaning and disinfecting characteristics in a very efficient manner, yet also leaves desired residual properties.
Further complicating matters is that if one tries to simply increase the level of biocide incorporated in the formulation, the cost of the final product can be adversely impacted and the nature of the product can be altered in a way that causes the product to have poor suspension characteristics. It would be particularly desirable to use relatively low levels of a biocide, yet find a way to improve biocidal activity of the existing amount of biocide.
Thus, a need still exists to develop improved hard surface cleaners that also are designed to disinfect floors.
It has been discovered that the combination of cationic polymers, preferably cationic emulsion polymers, even more preferably cationic emulsion polymers having an acrylate monomer moiety, will cause synergistic biocidal activity with quaternary ammonium biocides and/or substituted guanidine biocides, in hard surface cleaner formulations.
In one aspect the invention provides a cleaner having a pH of 7.0 or lower (preferably between 4.0 and 6.0). The cleaner includes (i) a biocidal disinfecting material selected from the group consisting of quaternary ammonium biocides and substituted guanidine biocides, (ii) a cationic polymer, (iii) a surfactant selected from the group consisting of nonionic and cationic surfactants, and (iv) water.
Where the biocidal disinfecting material is a quaternary ammonium biocide, particularly useful quaternary ammonium germicides are those described in U.S. Pat. No. 6,268,327. In this regard, quaternary ammonium biocides of this type have the nitrogen linked to four carbon-containing R groups and there is a salt-forming anionic member, such as a halide. The most preferred R groups are between 6 to 26 carbon atoms.
Particularly preferred exemplary quaternary ammonium salts which are quaternary ammonium biocides are alkyl ammonium halides such as cetyl trimethyl ammonium bromide, alkyl aryl ammonium halides such as alkyl dimethyl benzyl ammonium chloride, N-alkyl pyridinium halides such as N-cetyl pyridinium bromide, and the like. Other suitable types of quaternary ammonium salts may include those in which the molecule contains either amide or ester linkages such as octyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, N-(laurylcocoaminoformylmethyl)-pyridinium chloride, and the like. Other quaternary ammonium germicides are lauryloxyphenyltrimethyl ammonium chloride, cetylaminophenyltrimethyl ammonium methosulfate, dodecylphenyltrimethyl ammonium methosulfate, dodecylbenzyltrimethyl ammonium chloride, and chlorinated dodecylbenzyltrimethyl ammonium chloride.
Examples of such preferred quaternary ammonium biocides are the BTC(copyright), BARDAC(copyright), and HYAMINE(copyright) biocides, such as BTC 2125M. BTC biocides are available from Stepan Co., and BARDAC and HYAMINE biocides are available from Lonza, Inc.
We prefer to use these biocides at under 1 percent to minimize cost and reduce disruption to the other characteristics of the mixture. However, the concentration could be more, albeit the concentration could be as little as 0.001 percent by weight. Most preferably we prefer weight percentages between 0.10 percent and 0.5 percent when this type of germicide is used.
The biocidal disinfecting material can alternatively be a substituted guanidine anti-microbial agent. See generally U.S. Pat. No. 5,000,867 for compounds of this general class.
In the most preferred form the biocidal substituted guanidine compound may be a biguanide. In general, such a biguanide compound may contain one or more monomers of: 
In this formula R1 through R4 can be a variety of different moieties. Examples are aryl, alkyl, hydrogen or just bonds. Some of these are where R1 and R2 are alkylene chains optionally substituted by a phenyl radical (which itself optionally may be substituted by alkyl or alkoxy groups), and the other R groups may be hydrogen, C1-12 alkyl or C7-12 aralkyl. It is also possible that some of the R groups may be linked to form cyclic portions. The substituted guanidine (e.g. biguanide) anti-microbial agents also include the acid addition salt variants.
A particularly preferred bisbiguanide is 1,6-bis-(p-chlorophenyldiguanido)hexane in the form of the hydrochloride, acetate or gluconate, this compound is available from Avecia of Manchester, England.
The preferred concentration of the substituted guanide disinfectant in the cleaner is preferably that described above with respect to the quaternary ammonium disinfectants.
In preferred forms the water is at least 50 percent of the weight of the cleaner at the time of use. Of course, the formulation may be prepared as a concentrate, with the consumer diluting the concentrate in a bucket immediately prior to use.
In another preferred form the cleaner has an organic solvent which provides a wider range of cleaning capability to the cleaner (e.g. with respect to hydrophobic soils on the floor). Preferred amounts of organic solvent are between 0.05 percent and 10 of the cleaner, most preferably between 1 and 5 percent of the cleaner, with the solvent being a mixture of such solvents. A particularly preferred mixture of organic solvents is a mixture of two glycol ethers such as a mixture of diethylene glycol butyl ether (a/k/a butyl carbitol) and ethylene glycol hexyl ether (a/k/a hexyl cellosolve).
Further, a third solvent (such as propylene glycol or ethylene glycol) can be used with this preferred mixture. In an especially preferred form at least one of the three solvents has a boiling point of over 100xc2x0 C. so as to provide the final product with optimal visual characteristics on a floor or the like.
Where the product is intended as a floor cleaner, it is desirable to include a wax in the cleaner so as to leave a shine on the floor after the cleaning and disinfecting step has been completed. Preferred waxes are paraffin wax, carnuba wax and synthetic wax, or mixtures thereof. A particularly preferred wax is a nonionic paraffin sold under the name Michem Lube 743 supplied by Michaelman of Cincinnati, Ohio.
Another especially important attribute of the cleaner is the cationic polymer. It is preferably present at between 1 and 20 percent concentration, most preferably at about 6 to 8 weight percent of the cleaner at the time of use. Again, where the cleaner is supplied as a concentrate the percentages can be higher, subject to the dilution prior to use.
A wide variety of cationic polymers should be suitable for use with the present invention. This will normally be achieved by a polymer being functionalized with some nitrogen-containing moiety capable of becoming cationic.
The most preferred polymers are emulsion polymers such as those made from acrylate monomers at least in part. Examples of such polymers are Suretec NS 54, a cationic acrylate emulsion polymer supplied by Suretec, Inc. formed from a monomer mix of styrene, methyl methacrylate, dimethyl amino ethyl methacrylate, and butyl acrylate. Other example polymers are the Neocryl A series polymers from Avecia, Inc.
Preferred aspects of the cationic emulsion polymer are that there be some polymeric portion (e.g. acrylic, urethane, etc.) which is functionalized by a cationic group such as a nitrogen group. Particularly preferred polymers exceed 2000 in molecular weight. This is important because the polymer will then provide sufficient bulk to provide durability under floor use conditions.
The presence of a cationic portion is important. Without wishing to be bound by theory, we believe that polymers used to impart shine contain residual impurities that tend to quench the specific biocidal materials even if the impurities are present in only trace amounts.
As noted above, it is desirable that the cleaner, at the time of use, and preferably during storage, have a pH that is not basic. Moreover, the desirable properties of the cleaner are greatly enhanced if the pH is between 4 and 6. While an even lower pH is possible, that might begin to have adverse effects on the floor or other surface being treated, and/or place undesirable limitations on skin contact.
While a wide variety of nonionic and cationic surfactants are possible to include, we prefer to include only nonionic surfactants given that cationic surfactants sometimes have foaming and other characteristics making them somewhat more difficult to use for standard floor care purposes. The most preferred surfactants are the alkyl polyglucosides. Other nonionic surfactants should prove suitable, such as ethoxylates, pluronics, fatty ester nonionic surfactants, and ethanolamine nonionic surfactants.
Examples of preferred cationic surfactants, when they are used, are the Ammonyx surfactants available from Stepan of Northfield, Ill. However, many other cationic surfactants are believed suitable for use with the present invention.
The formulation optionally may also include a variety of other ingredients conventional in floor care (e.g. a chelating agent such as EDTA, a plasticizer such as tributoxy ethyl phosphate, and fragrance). Further, other ingredients that are not disruptive to the function of the product may also be included. In this regard, in some embodiments we also prefer to include a fluorosurfactant for additional visual effects.
In another aspect the invention provides a method of killing bacteria on a floor surface. One exposes the floor surface to a floor cleaner of the above type, thereby killing the bacteria.
It should be appreciated that the above compositions achieve surprising disinfectant results using relatively small amounts of disinfectant. Most importantly this is achieved without significantly adversely impacting on other desired attributes of the product (e.g. cleaning, shelf stability, residual shine, durability).
Because the amount of disinfectant can be reduced for a given level of disinfecting capability, the cost of the product can be reduced. Further, the product is suitable for long-term inventory and consumer storage.